Papers by Author: Min Wang

Abstract: Cu₁₁O₂ (VO₄)₆ powders have been synthesized by complexing Sol-Gel method using citric acid as chelate, calcined at different temperature without using any template. Techniques of X-ray diffraction (XRD) and scanning electron microscope (SEM) have been employed to characterize the as-synthesized materials. The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under UV-light. It revealed that temperature values can influence significantly on the morphologies and structures of the products.It also found that the sample prepared with the molar ratio of citric acid to metal inons be 2:1, pH=7 and calcinated under 500°C for 4 hours was pure triclinic Cu₁₁O₂ (VO₄)₆ phase.In this conditions, the sample had highest photocatalytic activity with the photodegradation rate was about 78.9% or so in 60min under 20W ultraviolet lamp.

Abstract: Bismuth vanadate (BiVO4) powders were synthesized by complexing Sol-Gel method using citric acid as chelate,calcined at different temperature and characterized with X-ray diffraction (XRD), scanning electron microsoope（SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. It revealed that temperature values can influence significantly on the morphologies and structures of the products.It also found that the sample prepared with the molar ratio of citric acid to metal inons be 2:1, pH=7 and calcinated under 400°C for 5 hours was pure monoclinic BiVO4 phase.In this conditions, the sample had highest photocatalytic activity with the photodegradation rate was about 94% or so in 20min under 250W halogen lamp.

Abstract: FeVO4 photocatalysts were synthesized by complexing Sol-Gel method using citric acid as chelate and characterized with X-ray diffraction (XRD), scanning electron microsoope(SEM, specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. It was found that the sample prepared with the molar ratio of citric acid to metal inons be 2:1, pH=7 and calcinated under 750°C for 4 hours was pure triclinic FeVO4 phase. In the experimental conditions used, the FeVO4 calcined at 750°C had highest photocatalytic activity with the photodegradation rate was about 85% or so in 150min under 250W halogen lamp.

Abstract: Cu₃V₂O₈ powder was prepared by the liquid phase precipitation method and characterized using XRD , SEM and BET. The photocatalytic decolorization of methyl orange in Cu₃V₂O₈ powder suspension was investigated using 20w UV light as light source．The result shows that the the liquid-phase precipitation method is a simple and effective method for Cu₃V₂O₈ powder preparation. It was found that the sample prepared with the n(V)/n(Cu)moral ratio be 2/3, pH=7 and calcinated under 750°C for 4 hours was pure triclinc Cu₃V₂O₈ phase.

Abstract: FeVO₄ photocatalysts were synthesized via a surfactant-assisted sol-gel method and characterized with X-ray diffraction (XRD), scanning electron microsoope （SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. The XRD patterns of no-surfactant-assisted, PEG-assisted, CTAB-assisted and SDS-assisted FeVO₄, indicate that diffraction peaks can be well indexed as triclinc FeVO₄. And the crystalline sizes of samples were evaluated as 113, 69, 66, 76 nm for FVO, FVO-PEG, FVO-CATB and FVO-SDS respectively.The addition of surfactant woul greatly affect the morphology of FeVO₄ photocatalysts, which can lead to different photocatalytic activities between them. In the experimental conditions used, the PEG-assisted FeVO₄ product had a much higher photocatalytic activity (the photodegradation rate was about 77% or so in 14h) than the other three products.